1. Field of the Invention
The present application relates to a crystalline scintillator body that emits light upon irradiation with radiation and to a radiation detector including the crystalline scintillator body.
2. Description of the Related Art
In an X-ray computed tomography (CT) apparatus used for medical practice, a scintillator emits light upon receiving x-rays through a body, and a photodetector detects the light from the scintillator. Japanese Patent Laid-Open No. 2012-131964 (also published as U.S. Patent Application Publication 2012/0292516) discloses a crystalline scintillator body (phase-separated crystalline scintillator body) including a plurality of columnar crystals (cylindrical phases) and another crystalline phase (matrix phase) in which the columnar crystals are present. In this crystalline scintillator body, the material forming the cylindrical phases has a different refractive index from the material forming the matrix phase. Consequently, this crystalline scintillator has a wave-guiding function. Scintillators having wave-guiding function can reduce crosstalk more than scintillators not having a wave-guiding function.
In the type of the above-cited patent document, a phase-separated scintillator including cylindrical phases made of a scintillator material having a higher refractive index than the material of the matrix phase can reduce crosstalk particularly effectively. The above-cited patent document discloses a NaI—RbI crystalline body as such a phase-separated scintillator. In this crystalline body, the NaI forming the cylindrical phases functions as a scintillator. Unfortunately, NaI is deliquescent.